The main idea is getting rid of stub types and using just type variables
See more detailed description at docs/fir/delegated_property_inference.md
The problem with stub types is that they need really special treatment
in many places, and on the other hand, there are no clear contracts on
how they should work (that regularly leads to bugs like KT-59529)
^KT-61060 Fixed
^KT-61075 Fixed
^KT-61077 Fixed
^KT-59529 Fixed
^KT-61633 Related
^KT-61618 Related
^KT-61740 Related
^KT-59107 Related
^KT-61747 Related
^KT-61077 Related
^KT-61781 Related
When BI/incomplete call is present in return argument, it will be
added to the main call-tree, leading to requirement violation in
`ConstraintSystemCompleter.getOrderedAllTypeVariables`
as after `FirBuilderInferenceSession.inferPostponedVariables` it will
be completed, and its type variables couldn't be found anymore
In K1, we actually do the same, but we are able to find type variables
of such calls due to architecture difference:
In K2, `getOrderedAllTypeVariables` uses FIR as the main source to
lookup
In K1, `getOrderedAllTypeVariables` uses resolution atom tree, where
candidate/CS of the call is still available after
`inferPostponedVariables`
In fact, all incomplete calls were analyzed in FULL mode according to
the contract of `FirBuilderInferenceSession.addPartiallyResolvedCall`.
Thus, it means we normally shouldn't add them to the main call-tree, but
accidentally do it as incomplete calls contain non-completed candidate
This particular commit addresses the problem partially, only
in cases when the expected return type for the lambda is Unit and when
the incomplete call is located in the last expression of the lambda
In such cases, we can skip the call from the last expression completely,
since all potential calls there were analyzed in FULL mode,
and couldn't introduce any useful info to the CS of the main call-tree
^KT-54294
After Kotlin-IDE-plugin is moved to intellij repository, this commit
updates contributing.md guide with corresponding references.
Other than that brief information on current repository is provided.
Nikita Bobko